The purpose of this research study is to assess the safety and effectiveness of a long-acting form of somatostatin (lanreotide, Ipstyle@) as a treatment of patients with acromegaly, the condition caused by excessive growth hormone secretion by a pituitary adenoma (benign tumor). The study is sponsored by Ipsen Biotech and will involve eighty patients at several different institutions, including approximately ten at the University of Pennsylvania.